If you thought you had discovered everything in Batman: Arkham City or, if not, it could be found on GameFAQs or in some other corner of the web, well, that's not so, says the game's studio. There are still "three or four" secrets in the game that no one has yet found, the game's director said in a panel discussion at London this weekend.

"Some of them we put in there that were really obscure were found within a week," Sefton Hill told London's Kapow! Comic Con, reported IGN. They didn't think anyone would solve Scarecrow's code, for example, but it was cracked in two days.

"But there are still three or four things that people haven't seen—some of them very subtle things," he said. One of them was in the game's demo, which "nobody has found - it's in there if you look hard enough."